@proceedings {487, title = {Plasma Bubble and Blob Events in the F-region Ionosphere}, year = {2021}, month = {03/2021}, publisher = {HamSCI}, address = {Scranton, PA (Virtual)}, abstract = {

The equatorial plasma bubbles (EPBs) and plasma blobs (enhancements) are, in general, the nighttime phenomena of ionospheric plasma irregularities in the F-region ionosphere. This study presents plasma bubble and blob events identified from the SWARM satellite constellation when it flies above the American continent. We have also simultaneously examined the behavior of total electron content (TEC), its depletions, and enhancements in the equatorial/low/mid-latitude F-region ionosphere detected from ground-based Global Positioning System (GPS) receivers in the American sector. The in situ observations of bubble and blob events are concurrently supported by GPS-TEC measurement from the ground. Additionally, the coordinated ground- and satellite-based observations indicate that the ground-based data show the variability of the background ionosphere prior, during, and later than the development time of the EPBs as seen by the SWARM. For this limited analysis, the plasma blob events are mostly seen at/nearby mid-latitude regions. Finally, we discuss the possible mechanism of the generation, evolution, and relationship between EPBs and plasma blobs in the F-region ionosphere.

}, url = {https://hamsci2021-uscranton.ipostersessions.com/?s=51-F0-AC-9D-0C-7E-D9-A3-FC-F1-2E-13-F2-6E-34-90}, author = {Sovit Khadka and Cesar Valladares and Andrew Gerrard} } @conference {401, title = {Neutral Winds in the Equatorial Thermosphere as Measured With the SOFDI Instrument (ePoster)}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

The Second-generation, Optimized, Fabry-Perot Doppler Imager (SOFDI), a triple-etalon Fabry-Perot interferometer, is designed to measure both nighttime and daytime thermospheric winds from OI 630-nm emission. These continual 24-hour observations of thermospheric winds made with SOFDI under the geomagnetic equator at Huancayo, Peru, during northern summer, provide a unique data set. Results obtained from these data set are compared to the equatorial ionization anomaly (EIA) derived from\ \ total electron content (TEC) and Jicamarca incoherent scatter radar (ISR) measurements of the pre-reversal enhancement (PRE). We investigate the dynamics of the EIA asymmetry in response to measured thermospheric winds. A direct relationship between the afternoon winds and the magnitude of the PRE is also reported. The large variability of winds is observed in the afternoon which is likely caused by synoptic tidal activity modulating gravity waves. Also, a comparison between the measured neutral winds to that obtained from Horizontal Wind Model 14 is demonstrated. These results confirm the role that the thermospheric winds play in modulating equatorial dynamics and further demonstrate the need for both zonal and meridional components of the wind flow.

}, author = {Sovit Khadka and Andrew Gerrard and John Meriwether} }